Origins of Naming
An opening is properly the term for the first phase of a chess game
(the other two being the middle-game and the end-game), and is
generally regarded as completed when all of a player's back-rank pieces have
been "developed" (ie. brought into play). An
opening can take as few as 8 moves or as many as 20 to complete
Models of Play
With the advent of the modern game
however, sequences of successful opening moves were increasingly studied
and developed by trial and error into principles and models of opening play
that are now termed "openings" in general. At the same time names
began to be used to describe the different openings for convenient reference
(although the names rarely described the actual characteristics of each
The actual number of possible openings is virtually limitless. White has a
choice of 20 first moves (16 by pawn, 4 by knight) and Black has the
same number of replies, making 400 different possible positions after
only one move each. These figures rise to 72,084 different positions
after two moves each (including en passant options), and more than
9,000,000 different possible legal positions after only three moves
All chess material tends to be organised genetically (ie. based on the
sequential order of moves that created the position) rather than
typologically (ie. based upon similarities of position reached).
This makes knowledge of transpositions between openings particularly
important, especially in the early stages of a game, as
the ensuing move "position" (and any further variation that follows) is
usually classified under the particular opening sequence most likely to have
brought about the position.
Identifying by Type and Name
There are no international rules governing the naming of openings, but a
general convention or policy has grown to be accepted among all leading
chess players and organisations over the years whereby recognised openings
are (mostly) referred to by an identifying "name" combined with a
Most openings are of one of the following "types":
- Opening (a series of moves by White developed and tested in play)
- Defence (a passive or aggressive opening initiated by Black)
- System (a series of structural moves made by one side independently of the other)
- Game (older term for opening, now rarely used)
- Gambit (a sacrificial move by White)
- Counter-Gambit (always initiated by Black)
- Attack (an active threat initiated by White)
- Counter-Attack (always initiated by Black)
- Variation (any alternative line of play, often widely accepted over time)
The identifying "name" is usually (but not always) associated with either:
- The characteristics of the position (ie. the piece or tactic involved).
- The "inventor" (ie. first discoverer) of the tactical position.
- The analyst who first described the positional strategy in depth in a book or article.
- The player (often not the originator) who first used the opening in strong tournament play.
- The tournament where its repeated use popularised the opening.
- The city or country where a group of players developed the opening.
Lastly, one opening line may have many names (sometimes changing over time
or according to country), while conversely one name may denote several